400 Bad Request errors 29 July 2025
Getting 400 Bad request errors on differing tables and different entities when trying to retrieve data today.
Forum Discussion
Hey everyone - just want to flag we have also experienced a sudden spike in Bad Request errors with the ErrorType: InvalidQueryStringException. This started at a similar time as reported here.
In our case, we have built-in retry logic and, in some cases, this logic reduces the page size of subsequent requests. In most cases the retry logic is working, which to me shows the issue is not an InvalidQueryStringException.
I opened a support case with the API Support team yesterday and I do have a reply advising they are escalating to the API Engineering team internally.
They also mentioned the AccountRight API can be sensitive to formatting, encoding, or combinations of $top and $filter values, especially at large page sizes ($top=1000). They therefore suggested we could try some initial steps at our end to improve the success rate of requests.
- Temporarily default to smaller $top values (e.g. 200 or 500) where filters are complex or involve collections (Lines/any(...)). While this increases call volume, it may avoid the errors in the short term.
- Try URL-encoding the entire $filter parameter, even if it worked unencoded before.
We've implemented the above 2 points but it's too early to suggest if this has had any meaningful impact. Overnight all our connections will perform their daily sync tasks so we'll have a better idea tomorrow.
Cheers Shem
